Effect of chemotherapy on the tumor microenvironment and anti-tumor immunity

An accumulating body of evidence demonstrates that conventional chemotherapy and targeted therapies result in cell death that can elicit an antitumor immune response. A number of distinct biochemical properties of chemotherapy-induced cell death have an important role in determining its immunogenicity by triggering ‘danger signals’ that can elicit a specific antitumor immune response. Chemotherapy can also exert other immune modulatory effects on a number of immune cells including dendritic cells, myeloid-derived suppressor cells, CD8⁺ T cells, and regulatory T cells. An understanding of the interactions between cytotoxic therapies and the immune system and the tumor microenvironment is crucial for the rational development of combination treatments of immunotherapy with conventional or targeted therapies to achieve a synergistic antitumor effect and improved treatment outcomes.